Light emitting device package and backlight unit using the same

ABSTRACT

An light emitting device package and a backlight unit using the same are disclosed, wherein light advancing upward from the light emitting device package can be refracted by a lens to enable the light having a uniform intensity to be emitted upwards to the advantage of efficiency and power consumption, even with a small number of light emitting devices.

This application claims the benefit of the Korean Application No.10-2006-0011060 filed emitting device on Feb. 6, 2006, the disclosure ofwhich is hereby incorporated by reference herein in its entirety.

BACKGROUND

This description relates to a light emitting device package and abacklight unit using the same.

A conventional light emitting diode is optically disposed with adome-shaped lens, and light is limitedly distributed to within apredetermined region with respect to a central axis. If a light emittingdiode is employed to manufacture a liquid crystal display (LCD) forbacklight unit, one potential problem is that an even lightcharacteristic cannot be obtained due to light emitting characteristicof the light emitting diode.

It implies that a considerable distance is needed to evenly combinelight radiated from the light emitting diode, making it difficult toattain a uniform light characteristic from a thin backlight unit. Inother words, a backlight unit using a light emitting diode suffers froma disadvantage of increasing the thickness of an LCD system.

FIG. 1 illustrates a light path from a lateral optical lens according toprior art, where a light emitting diode (LED.10) is disposed inside adome-shaped lens (20). The dome-shaped lens (20) is formed thereon withan inclined cone-shaped groove (21) and its side is formed with aV-shaped groove (22).

If light emitted from the LED 10 contacts a surface of the cone-shapedgroove (21), the light is reflected from the inclined conical groove(21) to be radiated sidewise of the lens. If light contacts the V-shapedgroove (22) of the lens (20), the light passes through the lens (20) tobe radiated sideways of the lens.

In other words, an LED for laterally emitting (or side-emitting) light{hereinafter referred to as a lateral (side-emission type) LED}according to the prior art serves to laterally radiate light emittedfrom the LED (10), using a lateral optical lens.

Meanwhile, in the injection-molded lens (20), a region corresponding toan apex (22 a) of the V-shaped groove (22) is formed with prominencesand depressions (unevenness) if closely looked at (for example, in lessthan a millimeter unit), such that light of the LED (10) emitted fromthe region is not radiated sideways of the lens (10) but upwards of thelens (10).

FIG. 2 is a schematic perspective view of an LED package of FIG. 1,where the LED is bonded to a slug, and the slug is disposed at sidesthereof with leads (31, 32) which are in turn electrically bonded to theLED.

Furthermore, the LED and the slug are molded by molding means in orderto expose a light emitting surface of the LED and the leads (31,32), andthe lens (20) of FIG. 1 encompassing the LED is bonded to the moldingmeans.

FIG. 3 is a light emitting distribution table of an LED packageaccording to the prior art, where it shows that a large amount of lightis radiated sidewise of the package as indicated in ‘a’ and ‘b’ of thedistribution table while a small amount of light is radiated through acenter of the package as indicated in ‘c’, ‘d’ and ‘e’ of thedistribution table.

FIG. 1 implies that although most of the light is emitted sideways ofthe lens, some of the light is radiated upwards of the lens. In otherwords, the LED package thus described cannot implement a perfect lightemission to lateral surfaces, such that if it is to be used as a lightsource for a display, light is partially emitted from the light emittingdiode relative to the center of the LED package, bringing about aproblem of making an even planar light source.

To be more specific, the partial emission of light relative to thecenter of the LED package results in creation of so-called lightirregularity, referred to as a hot spot phenomenon where spots aregenerated about a center of pixels displayed on a display, causingdegradation of picture quality on the display. FIG. 4 illustrates indetail one of the causes generating the hot spots.

If a size of a light emitting diode (10) is extremely small, an amountof light emitted to a lateral surface of a conventional lens increasesby being reflected from a surface (21) of the cone-shaped groove, but ifthe size of the light emitting diode (10) is extremely large, light (C)progressing at an angle less than a critical angle from the surface (21)of the cone-shaped groove exists to allow the light to be emitted froman upper surface of the lens, thereby generating the appearance of hotspots, because the surface (21) of the cone-shaped groove totallyreflects only the light (A) advancing at an angle larger than thecritical angle, out of the light irradiated from the light emittingdiode (10).

At this time, light (B) progressing to lateral surfaces of the lens hasnothing to do with hot spots, as shown in FIG. 4.

FIG. 5 illustrates a cross-sectional view of a light emitting diodepackaged in a printed circuit board according to the prior art, where aplurality of lateral light emitting diode packages (50) are packaged ina printed circuit board (60). A printed circuit board packaged withlateral light emitting diode packages is employed for a backlight unitas depicted in FIG. 6.

FIG. 6 is a schematic cross-sectional view of a light emitting diodeemployed for a liquid crystal display (LCD) for backlight unit accordingto the prior art.

In order to address the problem of the light emitted to the center ofthe light emitting diode package, an LCD backlight unit is mounted witha hot spot baffle plate (80). In other words, an LCD backlight unit (90)is configured in such a manner that hot spot baffle plates (80) aremounted on each light emitting diode package (70) packaged in theprinted circuit board (60), and a light guide plate (85) is positionedon an upper surface of the hot spot baffle plate (80), and an uppersurface distanced from the light guide plate (85) is disposed with anLCD (95) to assemble the backlight unit (90) and the LCD 95.

However, there is a disadvantage in the backlight unit (90) thusconstructed in that a plurality of light emitting diode packages (70)must be mounted thereon with hot spot baffle plates (80) calleddiverters to complicate the fabrication process.

There is another disadvantage in that if there is an erroneousarrangement of the hot spot baffle plates (80) on the plurality of lightemitting diode packages (70), spots similar to the hot spots aregenerated on a screen of a display. Still another disadvantage is thatthe display panel increases in thickness as much as the hot spot baffleplate (80).

SUMMARY

Accordingly, the present invention is directed to a light emittingdevice package and a backlight unit using the same that substantiallyobviates one or more problems due to limitations and disadvantages ofthe related art.

A first object of the present invention is to provide a light emittingdevice package and a backlight unit using the same adapted to refract bya lens light advancing upward from the light emitting device package,thereby allowing the light having a uniform intensity to be emittedupwards to the advantage of efficiency and power consumption, even witha small number of light emitting devices.

A second object is to provide an light emitting device package and abacklight unit using the same adapted to cluster a plurality of lightemitting devices into one package, thereby allowing light emitted fromeach light emitting device to smoothly get mixed, and the light mixed bya lens disposed on the light emitting device package to be uniformlyemitted upward.

A third object is to provide an light emitting device package and abacklight unit using the same capable of reducing the number of parts, acomplicated assembly process and a thickness of a liquid crystal display(LCD) panel.

A fourth object is to provide an light emitting device package and abacklight unit using the same adapted to apply a lens film integrallyformed with lens formations capable of uniformly refracting light upwardfrom packages mounted with a plurality of light emitting devices,thereby enabling to remove a process of attaching lenses to each packageunit.

A fifth object is to provide an light emitting device package and abacklight unit using the same adapted to use packages mounted with aplurality of light emitting devices for promotion of usage of spaces ina substrate, thereby allowing driving units to be positioned between thepackages and enabling to attach heat radiation means on an entireopposite surface of the substrate mounted with packages to the advantageof heat radiation efficiency.

In one general aspect, an light emitting device package comprises: apackage body mounted with an light emitting device; and an optical lensattached on an upper surface of the package body having a refractingsurface for emitting light emitted from the package body and dischargingthe light to an outside, and having a recess thereon.

In another general aspect, an light emitting device package and abacklight unit using the same comprises: a substrate; a plurality oflight emitting device packages mounted on an upper surface of thesubstrate; a plurality of optical lenses attached on each upper surfaceof the light emitting device packages each having a refracting surfacefor emitting light emitted from the light emitting device packages anddischarging the light to an outside, and having a recess thereon; and adiffusion plate disposed on the plurality of optical lenses.

In still another general aspect, an light emitting device package and abacklight unit using the same comprises: a substrate; a plurality oflight emitting device packages mounted on an upper surface of thesubstrate; a lens film disposed on each upper surface of the lightemitting device packages and formed with a plurality of optical lensformations each having a refracting surface for emitting light emittedfrom the light emitting device packages and discharging the light to anoutside, and having a recess thereon; and a diffusion plate disposed onthe lens film.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 illustrates a light path from a lateral optical lens according toprior art;

FIG. 2 is a schematic perspective view of a light emitting devicepackage of FIG. 1;

FIG. 3 is a light emitting distribution table of an light emittingdevice package according to the prior art;

FIG. 4 illustrates in detail one of the causes generating the hot spotsin an optical lens according to the prior art;

FIG. 5 illustrates a cross-sectional view of a light emitting diodepackaged in a printed circuit board according to the prior art;

FIG. 6 is a schematic cross-sectional view of a light emitting diodeemployed for a liquid crystal display (LCD) for backlight unit accordingto the prior art;

FIG. 7 is a cross-sectional view illustrating a light path via anoptical lens according to the present invention;

FIG. 8 is a cross-sectional view illustrating a light path via anoptical lens according to the present invention;

FIG. 9 is a cross-sectional view illustrating a light path where areflection structure is attached to a guide extension of an optical lensaccording to the present invention;

FIG. 10 is a perspective view of an optical lens according to thepresent invention;

FIG. 11 is a cross-sectional view illustrating a light path via anoptical lens formed thereon with a plurality of recesses;

FIG. 12 is a schematic cross-sectional view illustrating a lightemitting device package mounted with an optical lens. according to thepresent invention;

FIG. 13 is a schematic cross-sectional view illustrating a state where alug of a light emitting device package is inserted into a guide extenderof an optical lens according to the present invention;

FIG. 14 is a schematic cross-sectional view illustrating a package wherean optical lens is mounted on a substrate according to the presentinvention;

FIG. 15 is a schematic cross-sectional view illustrating a package wherea molding apparatus is formed with an optical lens formation accordingto the present invention;

FIGS. 16 a and 16 b are schematic cross-sectional views illustrating abacklight unit using an light emitting device mounted with an opticallens according to the present invention;

FIGS. 17 a and 17 e are schematic plans for manufacturing an lightemitting device package mounted with an optical lens according to anembodiment of the present invention;

FIG. 18 is a schematic cross-sectional view illustrating an lightemitting device package mounted with an optical lens according to anembodiment of the present invention;

FIG. 19 is a schematic plan illustrating a state where three lightemitting devices are mounted on an light emitting device packageaccording to an embodiment of the present invention;

FIG. 20 a schematic plan illustrating a rectangular light emittingdevice package according to the present invention;

FIG. 21 a schematic plan illustrating a state where a lens is mounted tothe light emitting device package of FIG. 20;

FIGS. 22 a and 22 e are schematic plans for manufacturing an lightemitting device package mounted with an optical lens according toanother embodiment of the present invention;

FIG. 23 is a schematic cross-sectional view illustrating an lightemitting device package formed with a molding apparatus disposed withanother optical lens formation in the processes of FIGS. 17 d and 22 d;

FIGS. 24 a and 24 b are schematic plans illustrating a state where anlight emitting device package is mounted with light emitting devicesaccording to the present invention;

FIG. 25 is a schematic plan illustrating a shape of a mounting plate ofa light emitting device package according to the present invention;

FIGS. 26 a and 26 b are schematic plans illustrating shapes of leads ofa light emitting device package according to the present invention;

FIG. 27 is a schematic cross-sectional view of a backlight unit using alight emitting device package according to the present invention;

FIG. 28 is a schematic cross-sectional view of another backlight unitusing a light emitting device package according to the presentinvention; and

FIGS. 29 a and 29 b are schematic plans of a backlight unit using lightemitting device packages according to the present invention.

DETAILED DESCRIPTION

Hereinafter, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

Referring to FIG. 7, an optical lens (100) according to the presentinvention is disposed therein with a hollow part (101) into which anlight emitting device (110) for emitting light can be positioned, asurface for refracting the light emitted from the light emitting device(110) and discharging to an outside, and a recess (102) disposedthereon. Preferably, but not necessary, the optical lens (100) has ashape of a bulging cap, and the recess (102) is formed at an upperregion positioned on a central axis (P) of the cap.

Referring again to FIG. 7, if the light emitting device (110) isdisposed inside the optical lens (100), the light irradiated from thelight emitting device (110) is refracted from the optical lens (100) tobe discharged to an outside. The recess (102) formed on an upper surfaceof the optical lens (100) serves to change the shape of the optical lens(100) to refract the light advancing the upper side of the lightemitting device (110).

Typically, a side-emission type light emitting device is in use for anLCD backlight having a light path sideways because intensity of thelight advancing upward is too strong, but the present invention canequalize the intensity of the light irradiated from the diffusion plate(120) by refracting the light progressing upward from the light emittingdevice packages.

FIG. 7 illustrates a track where the light irradiated from the lightemitting device (110) inside the optical lens (100) is refracted by theoptical lens (100) to be evenly incident on the diffusion plate (120).

Now, referring to FIG. 8, assuming that a position inside the opticallens (100) from which light is irradiated on a central axis (P) is givenas ‘O’, the light irradiated to a path up to 80 degrees is refractedfrom the optical lens (100) to advance upward. However, the lightemitted from 80 degrees to 90 degrees based on the central axis (P) ofthe optical lens (100) does not advance upward, even if it is refractedfrom the optical lens (100), only to advance to a lateral surface of theoptical lens (100).

FIG. 9 is a cross-sectional view illustrating a light path where areflection structure is attached to a guide extension of an optical lensaccording to the present invention, where a portion of the optical lens(100) is opened to allow the hollow part (101) therein to communicatewith an outside, and a tip end of the opened portion is connected to aguide extender (107).

The guide extender (107) includes a first extender (105) horizontallyextended to a tip end of the optical lens (100) and a second extender(106) vertically extended to the first extender (105) The guide extender(107) is so formed as to facilitate an easy installation of the opticallens (100) to the light emitting device package.

The guide extender (107) is disposed therein with an inclinedring-shaped reflection structure (121) to allow the light irradiatedfrom the lateral surface of the light emitting device to be transmittedupward as shown in FIG. 9.

Referring to FIG. 10, the optical lens (100) is formed thereon with acurved recess (102) for refracting the light inside the optical lens(100). The optical lens (100) may be curvedly or slantingly formed inorder to transmit the light upward with a uniform intensity.

FIG. 11 is a cross-sectional view illustrating a light path via anoptical lens formed thereon with a plurality of recesses, where theoptical lens (100) is formed thereon with an array of recesses (131,132), each recess spaced a predetermined distance apart, and the opticallens (100) is made to receive a uniform intensity of light thereon.

FIG. 12 is a schematic cross-sectional view illustrating an lightemitting device package mounted with an optical lens, where a packagebody (200) fabricated with a light emitting device is attached thereonwith the optical lens (100). The package body (200) comprises a heatslug (210. i.e., a heat conducting part); an light emitting device (220)bonded to an upper surface of the heat slug (210); leads (230)electrically connected to the light emitting device (220); and moldingapparatus (250) encompassing the light emitting device (220) and a partof the leads (230) and exposing a bottom surface of the heat slug (210).At this time, a wire (240) electrically connects the light emittingdevice (220) and the leads (230), as shown in FIG. 12.

FIG. 13 is a schematic cross-sectional view illustrating a state where alug of an light emitting device package is inserted into a guideextender of an optical lens, where the optical lens (100) disposed withthe guide extender (107) and a package disposed with a projection (260)are prepared for the fabricating process. Successively, the lug (260) onthe package is inserted into an inside of the guide extender (107). Thelug (260) of the package and the guide extender (107) of the opticallens (100) may be bonded by adhesive means.

FIG. 14 is a schematic cross-sectional view illustrating a package wherean optical lens is mounted on a substrate, where ring-shaped reflectionstructures (221) are attached on an upper surface of a substrate (300),and an light emitting device (210) is bonded to the upper surface of thesubstrate (300) exposed between the reflection structures (221), and theoptical lens (100) is bonded to an upper surface of the substrate (300)outside of the reflection structures (221).

Light laterally emitted from the light emitting device (210) in thepackage thus formed is reflected from the reflection structures (221),transmitted upward and prevented from being lost.

Referring back to FIG. 8, the light irradiated from the light emittingdevice on a path of 80-90 degrees cannot advance upward even ifrefracted by the lens for the light emitting device, but advance to aradial lateral direction from the optical lens, such that the reflectionstructures (221) can radiate upward the light advancing sideways tothereby enable to reduce the loss of the light.

In other words, each of the reflection structures (221) has aninclination capable of reflecting the light emitted on a path of 80-90degrees from the central axis (P) of the optical lens (100) andadvancing the light upward of the optical lens (100).

FIG. 15 is a schematic cross-sectional view illustrating a package wherea molding apparatus is formed with an optical lens formation, thepackage includes a heat slug (210), an light emitting device (220)bonded to an upper surface of the heat slug (210), leads (230) bonded tothe light emitting device (220) and a wire (240), and a molding unit(270) encompassing the light emitting device (220), the wire (240) and apart of the leads (230), and exposing a bottom surface of the heat slug(210) and formed thereon with a lug of an optical lens formation. Asmentioned above, the optical lens is disposed with a surface forrefracting light radiated from the light emitting device (100) anddischarging the light to an outside, and is also formed thereon with arecess.

FIGS. 16 a and 16 b are schematic cross-sectional views illustrating abacklight unit using a light emitting device mounted with an opticallens. As depicted in FIG. 16 a, the backlight unit comprises: asubstrate (310); a plurality of light emitting devices (311, 312)attached on an upper surface of the substrate (310); a plurality ofoptical lenses (321), each lens formed with a surface disposed thereinwith a hollow part for refracting light radiated from the light emittingdevices and discharging the light to an outside, and also formed thereonwith a recess with each hollow part disposed therein with light emittingdevice and bonded to the substrate (310); and a diffusion plate (350)disposed above the plurality of optical lenses (321).

Now, referring to FIG. 16 b, the backlight unit comprises: a substrate(310); a plurality of light emitting device packages (331, 332) attachedon an upper surface of the substrate (310); a plurality of opticallenses (341, 342) disposed with a surface formed with a hollow parttherein for refracting light radiated from the light emitting devicepackages (331,332) and discharging the light to an outside, and alsoformed thereon with a recess, and bonded to the light emitting devicepackages (331,332); and a diffusion plate (350) disposed above aplurality of optical lenses (341, 342). The substrate (310) is preferredto be formed in MCPCB (Metal Core PCB) or MPCB (Metal PCB).

The backlight unit is advantageously operated in such a manner that thelight advancing upwards of the light emitting devices or the lightemitting device packages is refracted and discharged upwards of thelight emitting devices or the light emitting device packages with auniform intensity, whereby a large area can be uniformly illuminated,even with only a small number of light emitting devices or lightemitting device packages, thereby enabling to improve the backlightlight efficiency and power consumption efficiency.

FIGS. 17 a and 17 e are schematic plans for manufacturing an lightemitting device package mounted with an optical lens according to anembodiment of the present invention. First, a lead frame is prepared,the frame including a mounting plate (400) and a plurality of leads(410) distanced from the mounting plate (400), as shown in FIG. 17 a.The lead frame includes a conventional structure and may be variablydesigned and modified, but the plurality of leads (410) must satisfy arequirement that they be distanced from the mounting plate (400). At thesame time, the plurality of leads (410) must be positioned about themounting plate (400), as illustrated in FIG. 17 a.

Successively, a plurality of light emitting devices (421, 422, 423, 424)are bonded to an upper surface of the mounting plate (400) (FIG. 17 b).Preferably, the plurality of light emitting devices (421,422, 423, 424)are horizontally structured to allow electrodes to be formed thereon.The plurality of light emitting devices (421, 422, 423, 424) and aplurality of leads (410) are electrically connected (FIG. 17 c). At thistime, the plurality of light emitting devices (421, 422, 423, 424) and aplurality of leads (410) are electrically connected via a wire, asdepicted in FIG. 17 c. Thereafter, a molding apparatus (450) is formedfor encompassing the plurality of light emitting devices (421, 422, 423,424) and parts of the plurality of leads (410) (FIG. 17 d). Lastly, alens is bonded to an upper surface of the molding apparatus (450), thelens formed with a surface for refracting light radiated from theplurality of light emitting devices (421, 422, 423, 424) and dischargingthe light to an outside, and formed thereon with a recess (FIG. 17 e).

FIG. 18 is a schematic cross-sectional view illustrating an lightemitting device package mounted with an optical lens according to anembodiment of the present invention. The light emitting device packagecomprises: a mounting plate (400); a plurality of leads (410) eachspaced a predetermined distance apart from the mounting plate (400); aplurality of light emitting devices (421, 422, 423, 424) bonded to anupper surface of the mounting plate (400); a conductive body forelectrically connecting the plurality of light emitting devices (421,422, 423, 424) to the plurality of leads (410); a molding apparatus(450) encompassing the plurality of light emitting devices (421, 422,423, 424) and parts of the plurality of leads (410); ); and an opticallenses (460) formed with a surface for refracting light radiated fromthe plurality of light emitting devices (421, 422, 423, 424) anddischarging the light to an outside, and also formed thereon with arecess (461) and bonded to the upper surface of the molding apparatus(450). The conductive body is a wire. Thus, the light radiated from theclustered plurality of light emitting devices as on package is mixed tobe uniformly irradiated upward by the lens disposed on the upper surfaceof the package.

FIG. 19 is a schematic plan illustrating a state where three lightemitting devices are mounted on an light emitting device packageaccording to an embodiment of the present invention, where it can benoted that three light emitting devices (421, 422, 423) fabricated inthe mounting plate (400) is molded to form a package.

FIG. 20 a schematic plan illustrating a rectangular light emittingdevice package according to the present invention, where the mountingplate (400) is fabricated thereon in series with seven light emittingdevices (421, 422, 423, 424, 425, 426,427), each light emitting devicespaced a predetermined distance apart, a plurality of leads (410)discretely arranged at both sides of the mounting plate (400) are bondedby the light emitting devices (421, 422, 423, 424, 425, 426,427) via awire (430), and the plurality of leads (410), the mounting plate (400)and the the light emitting devices (421, 422, 423, 424, 425, 426,427)are encompassed by the molding apparatus (450). The light emittingdevice package is fabricated with light emitting devices in series toallow forming in a rectangular shape.

FIG. 21 a schematic plan illustrating a state where a lens is mounted tothe light emitting device package of FIG. 20, where recesses (421, 422,423, 424, 425, 426, 427) are formed on an upper surface of an opticallens (460) on central axes (P1, P2, P3, P4, P5, P6, P7) of the lightemitting devices (421, 422, 423, 424, 425, 426,427), each light emittingdevice discretely fabricated in series. Therefore, the rectangularpackage is attached with lenses formed with recesses on central axes ofeach light emitting device, such that light emitted from each lightemitting device can be uniformly radiated upward.

FIGS. 22 a and 22 e are schematic plans for manufacturing an lightemitting device package mounted with an optical lens according toanother embodiment of the present invention. A lead frame is firstprepared, where the lead frame includes a mounting plate (400), aplurality of leads (410) each spaced a predetermined distance apart fromthe mounting plate (400) and a plurality of leads (401) extended to themounting plate (400) (FIG. 22 a). Next, a plurality of light emittingdevices (421, 422, 423, 424) is bonded on an upper surface of themounting plate (400) (FIG. 22 b). In other words, the light emittingdevices employed in the package according to the present exemplaryembodiment are preferably vertical light emitting devices formed withelectrodes thereon and thereunder.

Successively, the plurality of leads (410) discretely arranged from themounting plate (400) are electrically connected to the light emittingdevices (421, 422, 423, 424) (FIG. 22 c). Thereafter, a moldingapparatus (450) is formed to encompass the plurality of light emittingdevices(421, 422, 423, 424) and parts of the plurality of leads (410)(FIG. 22 d). Lastly, the optical lens (460) formed with a surface forrefracting light radiated from the plurality of light emitting devices(421, 422, 423, 424) and discharging the light to an outside, and alsoformed thereon with a recess (461) is bonded to the upper surface of themolding apparatus (450) (FIG. 22 e).

As a result, the light emitting device package according to anotherembodiment of the present invention comprises: a mounting plate (400)mounted with a plurality of leads (401); a plurality of leads (410) eachspaced a predetermined distance apart from the mounting plate (400); aplurality of light emitting devices (421, 422, 423, 424) bonded to anupper surface of the mounting plate (400); a conductive body forelectrically connecting the plurality of light emitting devices (421,422, 423, 424) to the plurality of leads (410); a molding apparatus(450) encompassing the plurality of light emitting devices (421, 422,423, 424) and parts of the plurality of leads (410); and an opticallenses (460) formed with a surface for refracting light radiated fromthe plurality of light emitting devices (421, 422, 423, 424) anddischarging the light to an outside, and also formed thereon with arecess (461) and bonded to the upper surface of the molding apparatus(450).

At this time, a structure including the mounting plate (400), the leads(410), the light emitting devices (421, 422, 423, 424), and the moldingapparatus (450) comprises a package body, where the optical lens (460)is excluded.

Consequently, the light emitting device package according to anotherembodiment of the present invention is such that, as the light emittingdevices are mounted and electrically connected to the mounting plate,only one time of wire bonding is performed for each light emittingdevice.

FIG. 23 is a schematic cross-sectional view illustrating an lightemitting device package formed with a molding apparatus disposed withanother optical lens formation in the processes of FIGS. 17 d and 22 d.

There is an advantage in the light emitting device package according toFIG. 23 in that the foregoing processes of separately manufacturing anoptical lens and bonding the optical lens in FIGS. 17 d and 22 d, can bedispensed with when the molding apparatus is formed and the optical lensformation is formed on the molding apparatus. As a result, the opticallens is integrally formed with the molding apparatus and molded with thesame material as that of the molding apparatus. In other words, themounting plate (400), the light emitting devices (421, 422), the moldingapparatus (451) encompassing the wire (430) and parts of the leads (415)and the optical lens formation (452) can be integrally performed byone-time molding process.

FIGS. 24 a and 24 b are schematic plans illustrating a state where anlight emitting device package is mounted with light emitting devicesaccording to the present invention.

First of all, as shown in FIG. 24 a, a mounting plate (500) is mountedthereon with four light emitting devices. In other words, a first row isarrayed with a red (R) light emitting device (511), and a green (G)light emitting device (512), while a second row is arrayed with a green(G) light emitting device (513) and a blue (B) light emitting device(514).

Referring now to FIG. 24 b, the mounting plate (500) is fabricatedthereon with three light emitting device. In other words, a first row isarrayed with a red (R) light emitting device (511), and a second row isarrayed with a green (G) light emitting device (513) and a blue (B)light emitting device (514). The purpose of packaging four lightemitting devices in the RGGB array, and three light emitting devices inthe RGB array is to cluster the light emitting devices for fabricationin an effort to embody white light in one package.

Meanwhile, it is preferred that the package in the present invention beconstructed with one of the red, green and blue light emitting devicesor with all the light emitting devices. As a result, light irradiatedfrom the plurality of light emitting devices via an optical lensdisposed on an upper surface of the package can be mixed and uniformlyemitted upwards.

FIG. 25 is a schematic plan illustrating a shape of a mounting plate ofa light emitting device package according to the present invention.

As illustrated in FIG. 25, a mounting plate (600) is thickly formed toallow a bottom surface of a mounting plate (600) to be exposed to amolding apparatus (620), thereby enabling to discharge heat generatedfrom the light emitting devices (610) packaged in the mounting plate(600) to the mounting plate (600). In other words, the mounting plate(600) functions as a heat sink for conducting the heat away from thelight emitting devices.

FIGS. 26 a and 26 b are schematic plans illustrating shapes of leads ofan light emitting device package according to the present invention.

Referring to FIG. 26 a, a part of a lead in a light emitting devicepackage is exposed to a lower surface of the molding apparatus (620),thereby enabling to discharge heat generated from the light emittingdevices (610) via the leads (631, 632). As noted above, if the leads(631, 632) are disposed at a lower surface of the molding apparatus(620), there is an advantage of mounting the light emitting devicepackage on a printed circuit board with solder by flip-chip bonding. Alead (660) is then protruded laterally from the molding apparatus (620)as shown in FIG. 26 b.

FIG. 27 is a schematic cross-sectional view of a backlight unit using alight emitting device package according to the present invention.

The backlight unit comprises: a substrate (700); a plurality of lightemitting device packages (801,802) mounted on an upper surface of thesubstrate (700); a plurality of optical lenses formed with a surface forrefracting light radiated from the plurality of packages (801, 802) anddischarging the light to an outside, and also formed thereon withrecesses and bonded to upper surfaces of the packages (801, 802); and adiffusion plate (900) disposed above the plurality of optical lenses.

The backlight unit is advantageously operated in such a manner that thelight advancing upwards of the light emitting device packages isrefracted and discharged upwards of the light emitting device packageswith a uniform intensity, whereby a large area can be uniformlyilluminated, even with only a small number of light emitting devicepackages, thereby enabling to improve the backlight light efficiency andpower consumption efficiency.

FIG. 28 is a schematic cross-sectional view of another backlight unitusing a light emitting device package according to the presentinvention. The backlight unit comprises: a substrate (700); a pluralityof light emitting device packages (811) mounted on an upper surface ofthe substrate (700); a film (820) formed with a surface for refractinglight radiated from the plurality of light emitting device packages(811) and discharging the light to an outside, and also formed thereonwith a plurality of optical lens formations (821, 822, 823, 824, 825)each disposed with a recess and positioned on each upper surface of thepackages (811); and a diffusion plate (900) disposed above the film(820).

Each of the light emitting device packages (811) is preferred to bepackaged with a plurality of light emitting devices, and each opticallens formation on each central axis of the light emitting devicepackages (811) is formed with a recess.

Therefore, the backlight unit is advantageously operated in such amanner that a plurality of packages fabricated with a plurality of lightemitting devices are disposed thereon with an optical lens filmintegrally formed with optical lens formations for uniformly refractinglight to enable to dispense with a process of attaching an optical lenfor each package unit.

FIGS. 29 a and 29 b are schematic plans of a backlight unit using lightemitting device packages according to the present invention, where asubstrate (700) is formed with packages each fabricated with a pluralityof light emitting devices. In other words, the plurality of lightemitting devices are red (R), green (G) and blue (B) light emittingdevices. Furthermore, a driving unit (851) is attached in between thepackages for driving the packages (811).

At this time, because each package (811) is formed with a plurality oflight emitting devices, the substrate (700) formed with the packages(811) excels a substrate formed with one light emitting device in viewof space utility. In other words, as illustrated in FIG. 29 a, thepresent invention is comprised of a backlight unit using the packages(811) packaged with a plurality of light emitting devices, such that adriving unit (851) can be positioned in between the packages (811).

As a result, radiation means (750) may be attached on an entire oppositesurface of the substrate (700) formed with the packages (811) to enableto enhance the heat radiation efficiency. To be more specific, if abacklight unit packaged with one light emitting device is constructed, aspace utility can be deteriorated over that of the present invention,and a driving unit is positioned on an opposite surface of the substratepackaged with the light emitting device to thereby decrease an area ofthe radiation means (750).

As apparent from the foregoing, there is an advantage in the lightemitting device package and a backlight unit using the same thusdescribed in that light advancing upward from the light emitting devicepackage can be refracted by a lens, thereby enabling the light having auniform intensity to be emitted upwards to the advantage of efficiencyand power consumption, even with a small number of light emittingdevices.

There is another advantage in that a plurality of light emitting devicescan be clustered into one package, thereby enabling light emitted fromeach light emitting device to smoothly get mixed, and the light mixed bya lens disposed on the light emitting device package to be uniformlyemitted upward.

There is still another advantage in that a film integrally formed withlens formations capable of uniformly refracting light upward frompackages mounted with a plurality of light emitting devices is appliedto thereby enable to remove a process of attaching lenses to eachpackage unit.

Although the present invention has been described with reference to thepreferred embodiments, it will be understood that the invention is notlimited to the details described thereof. Various substitutions andmodifications have been suggested in the foregoing description, andothers will occur to those of ordinary skill in the art. Therefore, allsuch substitutions and modifications are intended to be embraced withinthe scope of the invention as defined in the appended claims.

1. A light emitting device package comprising: a body including asurface on which at least one light emitting device is mounted; and atleast one optical lens on the surface of the body and covering the lightemitting device, wherein the optical lens includes a refractive mediumto refract light emitted from the light emitting device and passingthrough the refractive medium, and further includes a recess thereon. 2.The package as defined in claim 1, wherein the body includes a mountingplate, the package further comprising: a plurality of leads each spaceda predetermined distance apart from the mounting plate; a plurality oflight emitting devices on a surface of the mounting plate; connectorselectrically connecting the plurality of light emitting devices to theplurality of leads; and a mold encompassing the plurality of lightemitting devices and parts of the plurality of leads.
 3. The package asdefined in claim 1, wherein the body includes a mounting plate having aplurality of extended leads, the package further comprising: a pluralityof leads each spaced a predetermined distance apart from the mountingplate; a plurality of light emitting devices on a surface of themounting plate; connectors electrically connecting the plurality oflight emitting devices to the plurality of leads, each spaced apredetermined distance apart from the mounting plate; and a moldencompassing the plurality of light emitting devices and parts of theplurality of leads.
 4. The package as defined in claim 1, wherein thebody a heat sink; the at least light emitting device on an upper surfaceof the heat sink; leads electrically connected to the at least one lightemitting device; and a mold encompassing the at least one light emittingdevice and parts of the leads while exposing a bottom surface of theheat sink.
 5. The package as defined in claim 1, wherein a surface of atleast one optical lens is curved or includes a curve and an inclination.10. The backlight unit as defined in claim 9, wherein each of thepackages comprises: a mounting plate; a plurality of leads each spaced apredetermined distance apart from the mounting plate; the plurality oflight emitting devices on to a surface of the mounting plate; conductorselectrically connecting the plurality of light emitting devices to theplurality of leads; and a mold encompassing the plurality of lightemitting devices and parts of the plurality of leads.
 11. The backlightunit as defined in claim 9, wherein each of the packages comprises: amounting plate disposed with a plurality of extended leads; a pluralityof leads each spaced a predetermined distance apart from the mountingplate; the plurality of light emitting devices on a surface of themounting plate; conductors electrically connecting the plurality oflight emitting devices to the plurality of leads, each spaced apredetermined distance apart from the mounting plate; and a moldencompassing the plurality of light emitting devices and parts of theplurality of leads.
 12. The backlight unit as defined in claim 8,wherein a surface of the plurality of optical lenses is curved orincludes a curve and an inclination.
 13. The backlight unit as definedin claim 10, wherein the plurality of optical lens are integrally formedwith the mold and are molded with the same material as that of the mold.14. The backlight unit as defined in claim 8 further comprising at leastone driving unit to drive at least one package.
 15. The backlight unitas defined in claim 9, wherein each of the packages comprises: amounting plate on which four light emitting devices are mounted thereonwhere a first row is arrayed with a red light emitting device, and agreen light emitting device, while a second row is arrayed with a greenlight emitting device and a blue light emitting device.
 16. Thebacklight unit as defined in claim 9, wherein each of the packagescomprises: a mounting plate on which three light emitting devices arefabricated thereon, where a first row is arrayed with a red lightemitting device, and a second row is arrayed with a green light emittingdevice and a blue light emitting device.
 17. The backlight unit asdefined in claim 9, wherein each of the light emitting devices is spacedin series a predetermined distance apart and a mounting plated of apackage, and a recess is formed at an upper surface of the optical lensof the light emitting device packages.
 18. A backlight unit comprising:a substrate; a plurality of light emitting device packages mounted on asurface of the substrate; a film formed with a surface, wherein the filmrefracts light radiated from the plurality of light emitting devicepackages and passing through the film, and also formed on the film are aplurality of optical lens formations, each disposed with a recess andpositioned on each surface of the packages; and a diffusion platedisposed above the film.
 19. The backlight unit as defined in claim 18,wherein each of the light emitting device packages is packaged with aplurality of light emitting devices.
 20. The backlight unit as definedin claim 18, wherein each optical lens formation on each of the lightemitting device packages is formed with a recess.